Bolt



Sept 8, 1931. w. M. HORTON 1,822,657

' BOLT Filed March 29, 1950 E2226 t L L y/zamzm Patented Sept. 8, 1931 UNITED STATES PAT'ENT- OFFICE WILLIAM M. HORTON, OF OLEVELQND, OHIO, ASSIGNOR TO THELAMSON & SESSIONS COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO BOLT Application filed March 29, 1930. Serial No. 440,123.

This inventionrelates to improvements in bolts, particularly bolts having a portion directly beneath their heads which is called the shoulder and which is of greater cross- 5 section than the shank of the bolt, this shoulder being .adapted to be engaged by the material into which the bolt is set in order to prevent turning of the bolt in its hole. The ordinary carriage bolt 4 is of this general character.

The carriage bolt of usual construction presents certain disadvantages both as to the article itself and as tothe methods and tools for producing the same. Bolts are usually upset from wire of round cross-section, there being a die which is shaped to form the round shank and the'square shoulder, and a hammer having therein a cavity shaped to form the head of the bolt. The dieopening correo sponding to the shoulder necessarily has square corners. During the use of the die,

scale and dirt collect in these corners, and

under the heat resulting from the upsetting of the metal, this foreign material is hardened to such an extent that it becomes, in effect, a part of the die. Such foreign material prevents the formation of sharp corners on the blanks, the appearance of which is thereby spoiled to a greater or lesser extent, 0 and in practice this is consideredsufliciently serious to require the refinishing or the scrapping of the dies. Another disadvantage in respect to the article itself is that considerable force is required to drive the square shoulders of carriage bolts into wood or other compressible material, and such material is weakened thereby, the fibers of Wood, for instance, being broken by thepointed corners of the shoulder.

With regard to the manufacture of carriage bolts, the square opening in the die is not only diflicult to make but, when the die is hardened, the metal around the corners of this square opening is weakened, and when the diehas been in use for a time, and before it is otherwise worn out, cracks are apt to start from theseweakened points.

One of the objects ofthe present invcn tion, therefore, is the production of a shouldered bolt which, when the shoulder is driven less damage to the material into which it is driven.

Another object is the provision of a. bolt of this character which shall be devoid of sharp corners and whichshall present a good appearance even when made in a die that has been used fora considerable length of time.

A further object is the provision of a bolt which shall permit of the use of dies'devoid of sharp corners and hence not subject to cracks nor to filling upwith scale and the like, such dies giving long service with a consequent low die cost.

Another object is the provision of a bolt which shall permit the use of a die, the shoulder portion of which may be formed by drill.- ing three holes and connecting the periphcries of these three holes by milling flats along the sides of the shoulder portion, thereby effecting a considerable saving in the cost of production over that of a die with either a square hole or an elliptical hole.

Other objects and features of novelty will appear as I proceed with the description of that embodiment-of the invention which, for the purposes of the present application, I have illustrated in the accompanying drawings, in which Figs. 1 and 2 are elevational views taken at right angles to each other, showing a boltembodying the present invention;

Fig. 3 is an end View of the same;

Fig. 4 is a cross-section taken substantially on the line H of Fig. 2; and Fig. 5 is a diagrammatic view, on an enlarged scale, illustrating the form of the shoulder portion ofthe bolt.

In the drawings, the bolt is shown with an being preferred;

shoulder includes a straight portion 20' lying tween dies, the blank being formed in such case with a shank having a diameter equal to the pitch diameter of the threads. This detail affects the relative diameters of the portions 11 and 12 but is of no importance in so far as the present invention is concerned.

The shoulder 13, as indicated in Fig. 5, conforms to some extent to a parallelogram 14..

The four sides of the parallelogram are of equal length, but the angles maybeequal or two of them may be greater than the other two. The shoulder 13 also approaches to a certain extent an ellipse 15, the perimeter of the shoulder touching the ellipse at the extremities of its major and minor axes 16 and 17 respectively. In Fig. 5, the lower righthand quarter of the shoulder is divided up, for convenience in computing area, into sectors a and Z) of circles, a rectan le 0 and a triangle d. The radius of the circle 18, of which the sector a is a part, is one-half the length of the minor diameter 17 of the ellipse 15, and the radius of the circle 19, of which the sector 6 is a part, is of the order of onefourth the diameter 17, this exact proportion The perimeter of the between the points where the two arcs 18 and 19 are tangent to that side of the diamond 14. In this figure, the circle 21 represents the outer diameter of the threaded portion 12 of the bolt. Since the center of circle 18 is at the intersection of the two axes of ellipse 15, and since this intersection lies in the axis of the bolt, the two circles 18 and 21 are concentric. It is quite within the scope of the invention'to make the circles 18 and 21 coincident, which means that the smaller diameter of the shoulder will be the same as the outer diameter of the threads, but I prefer to'have the circle 18 of sli htly greater diameter than the circle 21, this g ifiere'nce in diameter being preferably a certain arbitrary constant, as for instance .20/1000 ,of an inch for bolts of ordinary size. This slight overhan of the shoulder beyond the threads of the %olt is of advantage where the shoulder is to be driven or fitted intoa hole formed in apiece of metal to receive it. If the overhang is omitted, and

the fit of the shoulder into its hole is sufficiently close to require the driving of the bolt into place, then the threads of the bolt are almost certain to be damaged. The. 20/1000 overhang is sufficient to provide clearance for the threads and yet is not sufiicient to'require any material added force for driving the bolt into wood or other similarly compressible mainto When a die for the production ofthe bolt 'is to be made, the workman first drills holes at the centers 22 and 22 'of a radius equal to the radius of circle 19. He then drills a third hole centered at 23 of a radius equal to the radius of circle 18. The flats 20 are then milled off, which is a relatively simple operation, most of the material having been removed by the drilling operations. Thereafter the hole for the shank of the bolt is drilled, this hole being also centered at 23 and having its periphery in the circle 21.

From the above description and from the illustration in Fig. 5, it will be apparent that the volume of the shoulder, as I construct it, is considerably less than what the volume would be were the shoulder formed with the cross-section of either the parallelogram 14 or the ellipse 15. It does not have the deleterious effect upon the material into which it is driven that it would have if the parallelogram shape were employed, and yet it has been found that it performs the function of a shoulder (prevention from turning) quite as effectively as does'a square-shoulder. My bolt is particularly desirable where the shoulder must enter a metal member, because it is easier to produce and maintain tools for punching the necessary hole than it is to produce and maintain tools for punching a square hole. Furthermore, the s uare holes tend to concentrate strains at t e corners thereof, and thereby weaken the material more than is the case where rounded holes to receive my bolts are used.

While in the foregoing description and in the accompanying drawings I have disclosed one particular embodiment of the invention more orless-in detail, I desire it tobe understood that such detailed disclosure has been resorted to primarily for the purpose of fully illustrating the invention in accordance with the requirements of the statute, and is not to be construed as amounting to a limitation upon the scope of the invention.

Having thus described my invention, I claim:

1. A bolt having a head and a threaded portion, and a shoulder between the head and threaded portion, said shoulder having four longitudinal fiat surfaces the opposite ones ofv which are parallel, and four cylindrical surfaces interposed between the fiat surfaces, the common center for two of said cylindrical surfaces lying outside the circles of the two remaining surfaces,

- 2. A bolt having a head and a threaded portion, and a shoulder between the head and threaded portion, said shoulder having four longitudinal fiat surfaces the opposite ones of which are parallel, and four cylindrical surfaces interposed between the flat surfaces, two of said cylindrical surfaces havin their axes in the principal axis of the b0 t and two of them having their axes parallel with but spaced from the axis of the bolt.

3. A bolt having a head and a threaded portion, and a shoulder between the head and threaded portion, said shoulder in cross-section having major and minor axes at right angles to each other, the perimeter of the shoulder at these axes meeting an ellipse formed upon the same axes, the perimeter of the cross-section of the shoulder on either side of said axes being formed as arcs of circles, the adjacent arcs being connected by straight lines.

4. A bolt having a shoulder for preventing rotation, said shoulder being shaped in cross-section as a parallelogram modified by arcs of circles interposed between the straight sides of the parallelogram, the radius of two opposite arcs being substantially one-half that of the two remaining arcs, and the straight sides being tangent to the circles.

In testimony whereof, I hereunto aflix my signature.

WILLIAM M. HORTON. 

